86778 has 16 divisors (see below), whose sum is σ = 192960. Its totient is φ = 28908.

The previous prime is 86771. The next prime is 86783. The reversal of 86778 is 87768.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (86771) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 750 + ... + 857.

It is an arithmetic number, because the mean of its divisors is an integer number (12060).

2⁸⁶⁷⁷⁸ is an apocalyptic number.

86778 is an abundant number, since it is smaller than the sum of its proper divisors (106182).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (96480).

86778 is a wasteful number, since it uses less digits than its factorization.

86778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1618 (or 1612 counting only the distinct ones).

The product of its digits is 18816, while the sum is 36.

The square root of 86778 is about 294.5810584542. The cubic root of 86778 is about 44.2727547432.

Subtracting 86778 from its reverse (87768), we obtain a triangular number (990 = T₄₄).

It can be divided in two parts, 8 and 6778, that added together give a triangular number (6786 = T₁₁₆).

The spelling of 86778 in words is "eighty-six thousand, seven hundred seventy-eight".